Rising water temperatures due to climate change are putting coral reefs in jeopardy, but a surprising discovery by a team of marine biologists suggests that very similar looking coral species differ in how they survive in harsh environments. “We’ve found that previously unrecognized species diversity was hiding some corals’ ability to respond to climate change,” said Iliana Baums, associate professor of biology at Penn State University. A scientific paper describing the team’s discovery will be published in the print edition of the Proceedings of the Royal Society B on Feb. 7, 2014. Baums led the international research team, including Jennifer Boulay, a Penn State graduate student; Jorge Cortes, professor at the University of Costa Rica; and Michael Hellberg, associate professor of biological sciences at Louisiana State University. The researchers sampled the lobe coral Porites lobata in the Eastern Pacific Ocean off the West Coast of Central America and genetically analyzed the samples to reveal differences among various sample locations. When the scientists analyzed their data they found an unexpected pattern: one that suggested two separate lineages of coral that look deceivingly similar and sometimes live together in the same location. As the genetic data confirmed, the samples were not all Porites lobata, as the researchers initially thought. Instead, some belonged to the species P. evermanni. “That surprised us,” Baums said. “These two lineages look identical and we thought they were all the same coral species, but evermanni has a very different genetic makeup. We knew about P. evermanni — it’s not a new species — but we didn’t expect to find it in the Eastern Pacific, which is a suboptimal environment for coral. Typically you find P. evermanni in the waters of the Hawaiian Islands.” Boulay wondered if the two species differed in the way they live. She found that P. evermanni was less susceptible to bleaching than P. lobata. Bleaching occurs when the symbiotic relationship that corals share with single-celled algae breaks down as a result of an increase in water temperature. “If water temperatures continue to rise, and they surely will, coral species that succumb to bleaching more easily will die,” Baums said. “So we’re going to see a shift in the relative abundance of these two species.” Boulay found other important differences: P. evermanni had many genetically identical clones, which means that this species is reproducing asexually by breaking apart, although P.… More:
The post Species Diversity in Coral Reefs: Very Similar Looking Coral Species Differ in How They Survive in Harsh Environments appeared first on reefs.com.